Re: 2.4 vm, program load, page faulting, ...

William Lee Irwin III
2003-03-17T14:59:36Z

On Sat, 15 Mar 2003, Paul Albrecht wrote:
>> ... Why does the kernel page fault on text pages, present in the page
>> cache, when a program starts? Couldn't the pte's for text present in the
>> page cache be resolved when they're mapped to memory?

On Mon, Mar 17, 2003 at 10:02:21AM -0500, Rik van Riel wrote:
> The mmap() syscall only sets up the VMA info, it doesn't
> fill in the page tables. That only happens when the process
> page faults.
> Note that filling in a bunch of page table entries mapping
> already present pagecache pages at exec() time might be a
> good idea. It's just that nobody has gotten around to that
> yet...

SVR4 did and saw an improvement wrt. page fault rate, according to
Vahalia.

I'd like to see whether this is useful for Linux.

-- wli